Where they begin by burning books, they will end by burning people.Who said it? Heinrich Heine (1797-1856).
Source: Almansor: A Tragedy (1823)
Thoughts on the quote: The original is in German: Dort wo man Bücher verbrennt, verbrennt man auch am Ende Menschen and I don't speak German. Wikiquote gives several alternate translations, but I forget where I read the exact one I have above.
In any translation, it speaks to the problem of the slippery slope of destroying freedom, step by step. The same sort of people who want to take away your right to read will, eventually, want to take away your right to breathe. Because the danger of reading is that it leads to thinking; but people will persist in thinking, even without books (books just make it a bit easier!)
So, celebrate banned books week by buying and reading some books, especially banned books. It's not just your right to read. It's your right to breathe.
More about the author: Heine was (per Wikipedia) a German poet, journalist, essayist and literary critic. Many of his books were banned in Germany due to their satirical attacks on Germany's rulers.